ON THE first day of hearings on next year's budget, City Council made clear what it wants to talk about this spring: property taxes and labor contracts - two topics that have caused headaches for Mayor Nutter's administration in recent weeks.

Administration officials fielded questions Monday about union negotiations - "Why is the city demanding the right to furlough workers?"; "Why isn't more money being reserved for a possible firefighters contract?" - and about the city's tax-collection efforts.

Negotiating with unions and collecting property taxes are usually the domain of the Mayor's Office. But recent events have sparked interest in longstanding problems on both fronts, and Council members are hoping to insert themselves into the dialogue through the budget hearings.

"I'm not quite sure where this body stands or what kind of standing we have with contract negotiations, but as you can tell, we're going to be involved, using this process and asking questions," Councilman Bobby Henon, the former political director of the powerful electricians' Local 98, told administration officials Monday.

Three of the city's four biggest unions have been in negotiation stalemates with Nutter since 2009, and Council found itself at ground zero of that battle two weeks ago when hundreds of union protesters swamped Council chambers and whistled and chanted at Nutter until he abandoned his annual budget address.

Henon said that Nutter's recent decision to take his dispute with the biggest union, District Council 33, to the state Supreme Court was "a little bizarre" and "just doesn't make sense to me."

Council President Darrell Clarke, who promised to get involved in negotiations after the Nutter protest but has remained mum on details, said Monday that he had never heard so many questions about union contracts from Council members.

Citing legal reasons, Everett Gillison, Nutter's chief of staff, declined to answer specific questions on ongoing negotiations with DC 33, but said the administration wants to end the standoff and is "continuing to insist on sitting down and talking."

"The give-and-take has to occur. At this point, there's been no give, no take," he said. "That's why we are where we are."

The other issue that will likely dominate this budget season is property taxes: how to implement the new Actual Value Initiative and how to collect the half-billion dollars owed to the city by delinquent property owners.

A recent PlanPhilly/ Inquirer investigation put the city's abysmal record on tax collections on full display, and the timing couldn't have been worse for Nutter. Now, the administration must push its message on AVI - which above all has been sold as a system based on fairness - while residents and Council members question how so many have been able to go years without paying taxes.

As Clarke put it, "That's kind of the conversation of the day: improving collections."

"Part and parcel of this whole AVI discussion is the fact that we keep leaving money on the table," Kenney said. "It's that anger that people are feeling."

Nutter earlier this year said he will invest $40 million and create a high-level position to tackle the problem. And City Finance Director Rob Dubow said Monday that the administration is pursuing new collection methods, such as seeking the right to freeze tax delinquents' business bank accounts until they pay up.